1. Field of the Invention
The present invention relates to heat sink clips, and more particularly to a heat sink clip which easily and securely attaches a heat sink on a heat generating package without the need for a tool.
2. Description of Prior Art
A computer central processing unit (CPU) is the core administrator of electrical signals for most contemporary personal computers. Continued development of CPUs has enabled them to perform more and more functions. Heat generated by CPUs has increased commensurately. Excessive heat can adversely affect the operational stability of the computer. Measures must be taken to efficiently remove the heat from the CPU. Typically, a heat sink having great heat conductivity is mounted on the CPU to remove heat therefrom. A clip is frequently used to firmly attach the heat sink to the CPU, thus achieving greater efficiency of heat transfer.
FIG. 5 illustrates a conventional clip for fastening a heat sink to a CPU, as disclosed in Taiwan Patent No. 270560. The clip is formed from a plate of resilient material, and is generally M-shaped. The clip includes a pressing portion 10, two elastic portions 12 extending from opposite ends of the pressing portion 10, and two clip arms 14 depending from distal ends of the elastic portions 12. Each arm 14 defines two slots 16, one above the other. The lower slots 16 of the arms 14 engagingly receive ears 19 of a socket on which the CPU is mounted. The clip thereby resiliently attaches the heat sink to an upper surface of the CPU. A handle 18 is formed at the higher slot 16 of each arm 14, for facilitating operation of the clip by hand or with a tool. However, if the handle 18 is operated by hand, it is inconvenient and uncomfortable, and may even hurt the operator""s hand. If the handle 18 is operated with a tool such as a screwdriver, the screwdriver is prone to slip and damage other nearby components on a motherboard on which the socket is mounted.
FIG. 6 illustrates another kind of clip for fastening a heat sink to a CPU, as disclosed in U.S. Pat. No. 6,061,239. Each of a pair of clips has a main body 10xe2x80x2. A pair of hooks 12xe2x80x2 extends from opposite ends of the main body 10xe2x80x2, for engaging in a chassis of a heat sink. An operating body 14xe2x80x2 above the main body 10xe2x80x2 is pivotally attached to the main body 10xe2x80x2. The operating body 14xe2x80x2 has a cam 16xe2x80x2 for pressing the heat sink onto a heat generating electronic package. The clip is convenient and safe to operate, and does not need a tool. However the operating body 14xe2x80x2 is effectively permanently mounted on the main body 10xe2x80x2. If another heat sink having a different size is used, the cams 16xe2x80x2 of the clips are unlikely to be able to fit properly and press the new heat sink. Usually, another pair of differently sized clips needs to be obtained. This is inconvenient and costly.
Accordingly, an object of the present invention is to provide a heat sink clip which easily and securely and mounts a heat sink on a CPU.
Another object of the present invention is to provide a heat sink clip which can be used for any of a variety of differently sized heat sinks.
In order to achieve the objects set out above, a heat sink clip in accordance with the present invention includes a main body, and an operating body rotatably attached to the main body. The main body comprises a central portion, and a pair of clipping portions depending from opposite ends of the central portion respectively. A concavity is defined in a side of the main body near one of the clipping portions. A pair of mounting portions depends from a middle of the main body. A claw is formed at an end of each mounting portion. The operating body comprises a shaft rotatably received in the claws of the main body, and a handle perpendicularly extending from one end of the shaft and receivable in the concavity. A cam is formed on a center of the shaft. A pair of annular recesses is defined in the shaft at opposite sides of the cam respectively, the recesses rotatably receiving the claws of the main body. When the handle is rotated, the cam is driven to press on a heat sink. The heat sink clip thus resiliently and firmly attaches the heat sink onto an electronic package. If the operating body needs to be replaced with another operating body having a different sized cam, the operating body is easily pulled out from the claws.
Other objects, advantages and novel features of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which: